Sodium-Ion Hybrid Battery Combining an Anion-Intercalation Cathode with an Adsorption-Type Anode for Enhanced Rate and Cycling Performance

Sodium-ion batteries ( SIBs) are based on natural abundant and low-cost materials and show a good chemical safety. They have thus become an alternative battery technology to conventional lithium-ion batteries. However, SIBs usually suffer from poor rate capability and insufficient cycling performance caused by the sluggish reaction kinetics of the large Na+ ions, restricting their practical application. Herein, we report a novel sodium-ion hybrid battery ( SHB) combining an anion intercalation-type graphite cathode material with an adsorption-type hierarchical porous carbon anode material. The hierarchical porous amorphous carbon is derived from a natural biomass template with macro-, meso-, and micro-pores as well as high specific surface area, which are beneficial for fast adsorption/desorption of Na+ ions. Consequently, attributed from the hybrid battery design, this SHB exhibits excellent rate capability and cycling performance with a reversible capacity of 80 mAhg(-1) at 2 C over a voltage window of 0-3.8 V and capacity retention of 87% after 1000 cycles at 10 degrees C.